Panasonic NR-B420M Service Manual page 3

Compressor does not operate.
Is power supply voltage
within ± 10% of rated
voltage at start of
operation?
YES
Is resistance of relay
approx. 33Ω ?
YES
Is running capacitor
OK?
YES
Is compressor coil
continuity OK?
Fig. 4
YES
Compressor operate.
(There is operation noise. but overload protector functions
and compressor stops; this occurs repeatedly.)
Multiple connections
NO
to same
electrical outlet?
Insufficient capacity
of room wiring.
Short circuit (0 Ω)
NO
or Open circuit (∞ Ω)
NO Short circuit (0 Ω)
Main coil broken.
NO
or Auxiliary coil broken.
Compressor locked.
(Resistances in both main and auxiliary coils
normal.)
Compressor motor
burned out.
(Motor coil resistance low.)
(Condenser temperature is low.)
---- 3 ----
Connect refrigerator
separately.
Increase capacity
of room wiring.
Replace
contactless relay
Replace running
capacitor
Replace
compressor.
Replace
compressor.
Replace
compressor.
Complete gas leakage.
Complete choke.
Faulty compression.
B420M/MS/MW, B480M/MS/MW,
B570M/MS/MW/D/D-*9, B53D2,
B643M/MS/MW/D/D-*9, B703M/MS/MW,
C603D, C703M/MS/MW/D
Fig. 3
Fig. 4
Auxiliary
Main